I haven't used these sails personally so from that POV perhaps I have no right to comment...

...that said...

1. Consistent with the design of most of the kayak sails that are marketed for non-Hobie kayaks this looks to me like a downwind-only sail which says volumes about the inherent problems of lack of stability, dangers of catastrophic flooding/re-entry after a capsize, and lack of upwind ability of most sit-in kayaks when it comes to sailing them.2. There is a reason that most sailing yachts have sails shaped more or less like a vertical blade and not like a perpendicular cup and that is that the vertical blade has been found to be the most versatile and effective sail design in a wide variety of conditions and points of sail. If you only want to go downwind the cup may be fine (similar to a spinnaker) but if you want to sail on all possible points of sail it is clear to me that the cup design is not the way to go.3. The Hobie sail and kayak are designed for each other, work very well together and a number of inexpensive user modifications have been created to 'improve' the standard set-up with e.g. roller reefing/furling, battens for improved downwind control, stays for the mast to improve sail shape & allow a jib to be used, mirage drive slot daggerboards. The Hobie sail will allow you to sail downwind, across the wind and upwind (a daggerboard being available for the Adventure to further enhance upwind performance). The sail is easy enough to stow and deploy. So I find it hard to believe that this sail will confer any benefits on the owner of a Hobie kayak over the stock standard Hobie sail.

Did you watch the video on the site? It is intriguing. I don't disagree with your comments, but I'd still like to hear from someone who has tried one..... no mast, no stress on the mast, compact, easy to "furl and unfurl". The question remains - anyone tried one?

I considered getting one to supplement the Hobie sail when we had our Oasis. I agree with stobbo that it wouldn't replace the Hobie sail which is a true upwind sail. Awhile back Kepnutz posted about using one. Searching for windpaddle and kepnutz will give you some good info like:viewtopic.php?f=69&t=10062

I totally agree with the previous responses. Just last week I was on a beam reach with the standard Hobie sail on an Oasis and absolutely enjoying the response out of the boat. You would never get that out of those cup style sail arrangements. By the way, I've been sailing a variety of boats over the last 40 years and I've learned what works and doesn't. The standard Hobie sail works.

I do hear you, and I do not want to sound disrespectful in continuing to ask if anyone has tried one of these. We are full-time on the road which means it ALL has to go with us all the time. We recently sold inflatable kayaks so we can purchase two Revos. Space saving anything, everything, all the time is extremely critical and that's why I asked if anyone had tried a wind paddle sail. I know it will have limitations, I'm just curious if anyone had actually tried one. Seeing it in the video is one thing, but I'm seeking experience as we won't be able to purchase, carry, store the Hobie sails. I know there are questions of what two masts, sails, etc. really mean in making the difference, but you'd have to see/understand we are also mtn. bikers, hikers, etc. and it's always about making compromises of space vs. tools of the hobbies being on the road 24/7/365.Thanks,billgill

The Hobie mast & sail can be stored/transported inside the Adventure Hull. I don't know if this is possible with Revos but you can certainly do it with the Adventure. I mention this in case it helps with storage while on the road.

I bought a WindPaddle to use with a folding kayak on a sea paddling holiday, but in fact I got almost no use out of it, because of very calm weather.

The advantages are that it folds up very small, needing no mast, and it doesn't need any fittings on the kayak apart from a pair of dees to clip on to.

It needs a moderate amount of breeze to hold it up, otherwise it just falls back on to your head. On the one occasion when, briefly, the wind got up enough, it bowled the kayak along nicely, at about the same rate I'd paddle. I looped the sheet behind my head to hold the sail up, leaving me both hands free for the paddle. Steering with the paddle, I could probably go about 45 degrees off the wind direction - I didn't try any more than that. If I'd needed to drop the sail in a hurry, I could just have ducked my head out of the sheet (which slants up quite high).

Some people say the WindPaddle is no better than sailing with an umbrella. If you can rig the umbrella for hands-free use, that may be true.

I've known people who have used these. Some have found them to be a device that can be tricky to use, others have loved it. I fall on the side of thinking that they're pretty cool. They do work in cross winds, you don't need to have the wind from directly behind you. Having said that, on this forum especially, you're going to get a lot of users who prefer the Hobie sail. That's not necessarily because they have a bias towards Hobie (although, most of us do) but it's also because the design of the sail for Hobie kayaks is a better design. There's a reason why virtually every modern day sailboat uses a sail like the ones that are used on the Hobie Kayaks, as opposed to the sail that you have mentioned. That style works better. If you don't have the option of trying a Hobie sail, the WindPaddle sail is a fun option. If you do have a Hobie kayak, you'll have more fun, and more capability with the Hobie sails.

On one of my pedalling trips I came across a couple of people in sit-ins who had deployed kites for sailing down wind.

I spotted the two kites first, way off in the distance in front of me, and spent several minutes wondering what on earth they were doing out in the middle of the sea because they didn't seem to be connected to anything - then, as they came closer, I spotted the kayaks and realised what was going on.

The kites were like a paraglider wing (i.e. no struts in the kite - which would make them very easy to stow). One obvious advantage of their kites over 'sea-level' sails was that they could fly them way up in the breeze - which they were doing - and they seemed to be bowling along very nicely downwind.

The 'pilots' seemed to be in perfect control sailing alongside each other and chatting but I was traveling in the opposite direction and they were quite a long way off from me as we passed each other, so I didn't get a good look at the set up they were using and I don't know any more about the whats/hows/whys however, from what I saw it looked like a pretty good option in the right conditions.